Printer keyboard



March 6, 1962 P. H. SHIRE PRINTER KEYBOARD Filed March 13, 1959 is v r// Z/ V/////////////// 7 E "I E H 3,023,696 Patented Mar. 6, 1962 3,023,696 PRINTER KEYBOARD Phillip H. Shire, Toledo, Ohio, assignor to Toledo Scale Corporation, Toledo, Ohio, a corporation of Ohio Filed Mar. 13, 1959, Ser. No. 799,352 2 Claims. (Cl. 101-93) This invention relates to key-operated mechanism for setting up type in a printer and in particular to an improved key for such mechanism.

The key is particularly useful in key-operated mechanism of the type shown in FIG. IV of U.S. Patent No. 2,746,384, issued on May 22, 1956, to R. 0. Bradley et al. The stems or screws of the number keys shown in such FIG. IV are adjustable so that each, in its depressed position, limits movement of a rocker bar to exactly that required to properly position a printing member operatively connected to the rocker bar. The adjustment of the stems has long presented a serious problem.

Heretofore, each of the stems or screws of the keys was adjustably held in an internally threaded sleeve which was slotted and crimped to retain the stem or screw in its adjusted position. The crimping often caused the stems to he held too tightly or too loosely, and often even those which worked well at first would loosen with use.

It is, accordingly, the principal object of this invention to provide means for retaining the adjustment of a key of the type used in key-operated mechanism for setting up type in a printer.

Another object of the invention is to provide a readily adjustable key of the type used in key-operated mechanism which is so constructed that it retains its adjustment automatically.

Other objects and advantages are apparent from the following description of a preferred embodiment of the invention.

According to the invention, each of the internally threaded sleeves of keys like the number keys shown in the foregoing FIG. IV is slotted in two diametrically opposed places at its end from which its stem or screw extends and a spring clip is inserted in such slots to bias the stem or screw to lock the stem or screw in adjusted position. Even though locked in position, the stem or screw is easily adjustable.

A preferred embodiment of the invention is illustrated in the accompanying drawings.

In the drawings:

FIG. I is a fragmentary elevational view of one bank of keys in a keyboard mechanism for setting up type in a printer;

FIG. II is a vertical sectional view taken along the line IIII of FIG. I; and

FIG. III is a detail view of one of the spring clips shown in FIG. I.

These specific figures and the accompanying description are intended merely to illustrate the invention but not to impose limitations on the claims.

The bank 1 of keys shown in FIG. I includes ten keys 2 representative of the numbers from zero through nine only four of which are shown for the sake of simplicity. The keys 2 are arranged selectively to engage and rock a rocker bar 3 pivotally mounted on pintles 4 extending from a base 5. The rocker bar 3 is pivoted on an axis parallel to its length and is exactly like in structure, function and operation to the rocker bar 33 shown in FIG. IV of the foregoing US. Patent No. 2,746,384. Downwardly depending arm 6 of the rocker bar 3 is attached to a cord 7. As the rocker bar 3 pivots, a printing member (not shown), such as a type wheel or sector, operatively connected to the cord 7 moves to a corresponding position.

The keys 2 representative of the numbers from one through nine are slidably mounted while the one representative of the number zero is stationarily mounted.

The stationary zero key 2 is the right hand key as viewed in FIG. I; it includes an internally threaded sleeve or tubular member 8 having a threaded end extending through a plate 9, there being a nut 10 received by such threaded end holding the sleeve 8 in a fixed position. A second plate 11 having a Z-bend at each end is secured to the base 5 and plate 9 is attached to the bent portions so that it lies parallel to but displaced from the second plate 11 throughout the greater portion of its length. The internally threaded sleeve 8 receives a stem or screw 12 having a head 13 extending below the sleeve as viewed in FIG. I. The position of the screw 12 is adjusted by trial and error until it limits pivotal movement of the rocker bar 3 to exactly that required to position the associated printing member to print a zero, the rocker bar 3 being continuously urged about its axis toward the keys 2 by means of a return spring (not shown) associated with the associated printing member. Such a return spring is shown and described in the hereinbefore referred to US. Patent No. 2,746,384. The mechanism is shown in its zero printing position in FIG. I.

Each of the slidably mounted keys 2 is identical and includes an internally threaded sleeve or tubular member 14 that is slidably mounted in aligned holes of the plates 9 and 11 i.e., in a direction transverse to the pivotal axis of the rocker bar 3. The sleeve 14 is formed with a collar 15. A helical compression spring 16 encircles the sleeve 14 and is held compressed between the collar 15 and plate 9 so as to urge the key toward its undepressed position, the collars 15 being cushioned by means of a resilient pad 17 when they return to their undepressed positions. The internally threaded sleeve 14 receives a stem or screw 18 having a head 19 extending below the sleeve. The position of the screw is adjusted by trial and error until when the key 2 is in its depressed position it limits pivotal movement of the rocker bar 3 to exactly that required to properly position the associated printing member. Each of the screws 18 extends from its sleeve 14 a distance which is different from every other one. These distances are so adjusted that when none of the slidable keys 2 is depressed the stationary key 2 positions the rocker bar 3 to set up zero on the printing member and when one of the slidable keys 2 is in its depressed position it sets up the printing member to print that one of the numbers from one through nine which corresponds to such depressed key 2. Buttons (not shown) serve as pads on the ends of the slidable keys 2 remote from the heads 19 to protect the operators fingers and also to carry indicia corresponding to the position of the printing member as determined by that particular one of the keys 2.

A latch bar 20 is pivotally mounted on cone pointed screws 21 threaded through the Z-shaped portions of the plate 11, the screws 21 being held in adjusted position by means of lock nuts 22. A spring 23 mounted on one of the cone pointed screws 21 has one of its ends anchored to the plate 11 and its other end hooked over the edge of the latch bar 20. The spring 23 is tensioned to continuously urge the latch bar 20 about its pivotal axis towards the keys 2. The latch bar 20 has a beveled edge 24 adapted to catch over one of the collars 15 when a slidable key 2 is depressed to hold such key in its depressed position. The cooperating portions of the collars 15 and latch bar 20 are such that the depression of any slidable key 2 releases by cam action any other key that might have previously been depressed. Depression of the keys 2 is in opposition to the springs 16 which are compressed between the plate 9 and the collars 15 to urge the keys 2 toward their non-depressed positions.

Hence, the latch bar 20 functions to hold the last operated key in operated position. The latch bar 26 has an arm 25 connected with a common actuating member 26 by means of which the keyboard can be cleared.

The adjustment of the screws 12 and 18 has long presented a serious problem. At best the adjustment is time consuming because of the great number of keys 2 in a keyboard, there being ten keys in the bank 1 of keys which when multiplied by a number of banks becomes a relatively large number. Modern industrial printers often have great numbers of banks of keys. Each of the screws 12 and 18 must be adjusted individually so that it accurately rocks its rocker bar to properly position the associated printing member.

Heretofore, each of the screws was held in its internally threaded sleeve which was slotted and crimped to retain the screw in its adjusted position. The crimping often caused the screw to be held too tightly or too loosely. If it was too tight, it was difficult to turn the screw to make the adjustment. If it was too loose, the adjustment became lost in making the trial run to see if the adjustment was correct. Often even the screws which worked well at first would loosen with use, since sometimes the keyboards are struck violently in the field, and in any case the keyboards are subjected to heavy use in most installations.

The keys 2 of the invention are readily adjustable, yet nevertheless retain their adjustment automatically. Each of the sleeves 8 and 14, at its end nearest the rocker bar 3, is provided with a pair of diametrically opposed slots 27 which are tilted (for example 10 degrees) with respect to the longitudinal axis of the sleeve. A spring clip 28 has its ends 29 located in the slots 27 and partly encircles the screw in the sleeve to hold the screw in its adjusted position. As shown in FIG. III in their normal positions, the ends 29 of the spring clip 28 are relatively close together, the ends 29 being sprung or spread apart by the body of the screw when it is in place in the sleeve. The spring clip 28 biases the screw toward a side of the sleeve making the screw relatively difiicult to turn so that the screw is locked in its adjusted position. Even though locked in position, the screw is easily adjustable,

4 the spring bias being strong enough to keep the screw automatically in adjusted position during use of the key-operated mechanism, but being overcome quite easily during normal adjustment of the screw.

Various modifications in specific details of construction and arrangement of the parts of the structure may be made without departing from the scope of the claims.

Having described the invention, I claim:

1. In a type positioning device for a printer, in combination, a rocker bar, pivoted on an axis parallel to its length, for driving a printing member, and a plurality of keys each including a screw arranged to engage and position the rocker bar, an internally threaded sleeve which receives the screw in a selected position, slots in the end of the sleeve nearest the rocker bar tilted with respect to the longitudinal axis of the sleeve, and a spring clip in the slots at least partly encircling and engaging the screw externally of the sleeve to hold the screw in its selected position during use of the type positioning device, the clip permitting the screw to be turned in the sleeve in making adjustments.

2. A key comprising an internally threaded sleeve, a screw so received in the sleeve that an end of the screw extends from the sleeve, slots in the end of the sleeve from which the screw extends tilted with respect to the longitudinal axis of the sleeve, and a spring clip in the slots at least partly encircling and engaging the screw externally of the sleeve and cooperating with thread crests on the screw to hold the screw adjustably in adjusted position in the sleeve.

References Cited in the tile of this patent UNITED STATES PATENTS 1,017,770 Latshaw Feb. 20, 1912 1,160,435 Morey Nov. 16, 1915 2,346,584 Jacob Apr. 11, 1944 2,594,088 Sonnenann et a1 Apr. 22, 1952 2,746,384 Bradley et al. May 22, 1956 FOREIGN PATENTS 204,316 Switzerland July 17, 1939 

